amazing trader I follow on twitter who shorted all of the fall on Friday said he'd hold on to a chunk over the weekend, and he just closed the rest for huge gains on the gap down.
How would someone have known that it would fall even further? He had such confidence and was correct as usual.
Most on twitter seemed to be expecting a bounce.
I wonder what 'method' these people who seem to have a crystal ball use?
There is absolutely no way to know. Can you imagine all the things that could have happened over the weekend to make it gap up? Holding after the close on Friday is very tricky. The same thing happened around the Greece news. How can you forecast on Friday before close what developments there will be over the weekend when there are negotiations or things like this when we deal with political issues?
Now I would hazard a guess that when we closed on the low, this might have implied to the trader that the more likely scenario was a gad down opening. If you look at the daily bars every Friday, find the big ones over the years, see where they close in relation to the day, and then look at the bar where it opens on Sunday. I haven't done this because I don't want to gamble like this, but perhaps there is a trend that becomes obvious?
The really risky thing is that stops are difficult. Whereas during the day, and even overnight, you can generally get out within a point. But if you went long into the close on Friday, the last print in the NQ that I see is at 4191, and the very first print is at 4183, so even if you want to deal with a stop that is a few points, you may be in for a surprise.
The trader you mention though already made a killing, the worst that would have happened is he would have made less on the contracts he already shorted from higher up if the opening did in fact gap up, he was willing to accept the risk, and he more than likely had calculated that this move was profitable more often then not and hence would make the exact same trade the next time that the same conditions set up.
So in conclusion, there is really no way to know, its all just a matter of balancing risk with reward, and making sure you're on the right side of a statistical edge.